” Until the Newtown horror, the three worst K–12 school shootings ever had taken place in either Britain or Germany.

Almost all of the public-policy discussion about Newtown has focused on a debate over the need for more gun control. In reality, gun control in a country that already has 200 million privately owned firearms is likely to do little to keep weapons out of the hands of criminals. We would be better off debating two taboo subjects — the laws that make it difficult to control people with mental illness and the growing body of evidence that “gun-free” zones, which ban the carrying of firearms by law-abiding individuals, don’t work. ”

First, the mental-health issue. A lengthy study by Mother Jones magazine found that at least 38 of the 61 mass shooters in the past three decades “displayed signs of mental health problems prior to the killings.”

Gun-free zones have been the most popular response to previous mass killings. But many law-enforcement officials say they are actually counterproductive. “Guns are already banned in schools. That is why the shootings happen in schools. A school is a ‘helpless-victim zone,’”

Lott offers a final damning statistic: “With just one single exception, the attack on congresswoman Gabrielle Giffords in Tucson in 2011, every public shooting since at least 1950 in the U.S. in which more than three people have been killed has taken place where citizens are not allowed to carry guns.” “